fiv/fastiv-view.c

390 lines
11 KiB
C

//
// fastiv-view.c: fast image viewer - view widget
//
// Copyright (c) 2021, Přemysl Eric Janouch <p@janouch.name>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
//
#include <math.h>
#include <stdbool.h>
#include <gtk/gtk.h>
#ifdef GDK_WINDOWING_X11
#include <gdk/gdkx.h>
#endif // GDK_WINDOWING_X11
#ifdef GDK_WINDOWING_QUARTZ
#include <gdk/gdkquartz.h>
#endif // GDK_WINDOWING_QUARTZ
#include "fastiv-io.h"
#include "fastiv-view.h"
struct _FastivView {
GtkWidget parent_instance;
cairo_surface_t *surface;
bool scale_to_fit;
double scale;
};
G_DEFINE_TYPE(FastivView, fastiv_view, GTK_TYPE_WIDGET)
enum {
PROP_SCALE = 1,
PROP_SCALE_TO_FIT,
N_PROPERTIES
};
static GParamSpec *view_properties[N_PROPERTIES];
static void
fastiv_view_finalize(GObject *gobject)
{
FastivView *self = FASTIV_VIEW(gobject);
cairo_surface_destroy(self->surface);
G_OBJECT_CLASS(fastiv_view_parent_class)->finalize(gobject);
}
static void
fastiv_view_get_property(
GObject *object, guint property_id, GValue *value, GParamSpec *pspec)
{
FastivView *self = FASTIV_VIEW(object);
switch (property_id) {
case PROP_SCALE:
g_value_set_double(value, self->scale);
break;
case PROP_SCALE_TO_FIT:
g_value_set_boolean(value, self->scale_to_fit);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID(object, property_id, pspec);
}
}
static void
get_surface_dimensions(FastivView *self, double *width, double *height)
{
*width = *height = 0;
if (!self->surface)
return;
cairo_rectangle_t extents = {};
switch (cairo_surface_get_type(self->surface)) {
case CAIRO_SURFACE_TYPE_IMAGE:
*width = cairo_image_surface_get_width(self->surface);
*height = cairo_image_surface_get_height(self->surface);
return;
case CAIRO_SURFACE_TYPE_RECORDING:
(void) cairo_recording_surface_get_extents(self->surface, &extents);
*width = extents.width;
*height = extents.height;
return;
default:
g_assert_not_reached();
}
}
static void
get_display_dimensions(FastivView *self, int *width, int *height)
{
double w, h;
get_surface_dimensions(self, &w, &h);
*width = ceil(w * self->scale);
*height = ceil(h * self->scale);
}
static void
fastiv_view_get_preferred_height(
GtkWidget *widget, gint *minimum, gint *natural)
{
FastivView *self = FASTIV_VIEW(widget);
if (self->scale_to_fit) {
double sw, sh;
get_surface_dimensions(self, &sw, &sh);
*natural = ceil(sh);
*minimum = 1;
} else {
int dw, dh;
get_display_dimensions(self, &dw, &dh);
*minimum = *natural = dh;
}
}
static void
fastiv_view_get_preferred_width(GtkWidget *widget, gint *minimum, gint *natural)
{
FastivView *self = FASTIV_VIEW(widget);
if (self->scale_to_fit) {
double sw, sh;
get_surface_dimensions(self, &sw, &sh);
*natural = ceil(sw);
*minimum = 1;
} else {
int dw, dh;
get_display_dimensions(self, &dw, &dh);
*minimum = *natural = dw;
}
}
static void
fastiv_view_size_allocate(GtkWidget *widget, GtkAllocation *allocation)
{
GTK_WIDGET_CLASS(fastiv_view_parent_class)
->size_allocate(widget, allocation);
FastivView *self = FASTIV_VIEW(widget);
if (!self->surface || !self->scale_to_fit)
return;
double w, h;
get_surface_dimensions(self, &w, &h);
self->scale = 1;
if (ceil(w * self->scale) > allocation->width)
self->scale = allocation->width / w;
if (ceil(h * self->scale) > allocation->height)
self->scale = allocation->height / h;
g_object_notify_by_pspec(G_OBJECT(widget), view_properties[PROP_SCALE]);
}
static void
fastiv_view_realize(GtkWidget *widget)
{
GtkAllocation allocation;
gtk_widget_get_allocation(widget, &allocation);
GdkWindowAttr attributes = {
.window_type = GDK_WINDOW_CHILD,
.x = allocation.x,
.y = allocation.y,
.width = allocation.width,
.height = allocation.height,
// Input-only would presumably also work (as in GtkPathBar, e.g.),
// but it merely seems to involve more work.
.wclass = GDK_INPUT_OUTPUT,
// Assuming here that we can't ask for a higher-precision Visual
// than what we get automatically.
.visual = gtk_widget_get_visual(widget),
.event_mask = gtk_widget_get_events(widget) | GDK_SCROLL_MASK |
GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK,
};
// We need this window to receive input events at all.
GdkWindow *window = gdk_window_new(gtk_widget_get_parent_window(widget),
&attributes, GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL);
// Without the following call, or the rendering mode set to "recording",
// RGB30 degrades to RGB24, because gdk_window_begin_paint_internal()
// creates backing stores using cairo_content_t constants.
//
// It completely breaks the Quartz backend, so limit it to X11.
#ifdef GDK_WINDOWING_X11
// FIXME: This causes some flicker while scrolling, because it disables
// double buffering, see: https://gitlab.gnome.org/GNOME/gtk/-/issues/2560
//
// If GTK+'s OpenGL integration fails to deliver, we need to use the window
// directly, sidestepping the toolkit entirely.
if (GDK_IS_X11_WINDOW(window))
gdk_window_ensure_native(window);
#endif // GDK_WINDOWING_X11
gtk_widget_register_window(widget, window);
gtk_widget_set_window(widget, window);
gtk_widget_set_realized(widget, TRUE);
}
static gboolean
fastiv_view_draw(GtkWidget *widget, cairo_t *cr)
{
FastivView *self = FASTIV_VIEW(widget);
if (!self->surface ||
!gtk_cairo_should_draw_window(cr, gtk_widget_get_window(widget)))
return TRUE;
GtkAllocation allocation;
gtk_widget_get_allocation(widget, &allocation);
gtk_render_background(gtk_widget_get_style_context(widget), cr, 0, 0,
allocation.width, allocation.height);
int w, h;
get_display_dimensions(self, &w, &h);
double x = 0;
double y = 0;
if (w < allocation.width)
x = round((allocation.width - w) / 2.);
if (h < allocation.height)
y = round((allocation.height - h) / 2.);
// FIXME: Recording surfaces do not work well with CAIRO_SURFACE_TYPE_XLIB,
// we always get a shitty pixmap, where transparency contains junk.
if (cairo_surface_get_type(self->surface) == CAIRO_SURFACE_TYPE_RECORDING) {
cairo_surface_t *image =
cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w, h);
cairo_t *tcr = cairo_create(image);
cairo_scale(tcr, self->scale, self->scale);
cairo_set_source_surface(tcr, self->surface, 0, 0);
cairo_paint(tcr);
cairo_destroy(tcr);
cairo_set_source_surface(cr, image, x, y);
cairo_paint(cr);
cairo_surface_destroy(image);
return TRUE;
}
// XXX: The rounding together with padding may result in up to
// a pixel's worth of made-up picture data.
cairo_rectangle(cr, x, y, w, h);
cairo_clip(cr);
cairo_scale(cr, self->scale, self->scale);
cairo_set_source_surface(
cr, self->surface, x / self->scale, y / self->scale);
cairo_pattern_t *pattern = cairo_get_source(cr);
cairo_pattern_set_extend(pattern, CAIRO_EXTEND_PAD);
// TODO(p): Prescale it ourselves to an off-screen bitmap, gamma-correctly.
cairo_pattern_set_filter(pattern, CAIRO_FILTER_GOOD);
#ifdef GDK_WINDOWING_QUARTZ
// Not supported there. Acts a bit like repeating, but weirdly offset.
if (GDK_IS_QUARTZ_WINDOW(gtk_widget_get_window(widget)))
cairo_pattern_set_extend(pattern, CAIRO_EXTEND_NONE);
#endif // GDK_WINDOWING_QUARTZ
cairo_paint(cr);
return TRUE;
}
#define SCALE_STEP 1.4
static gboolean
set_scale_to_fit(FastivView *self, bool scale_to_fit)
{
self->scale_to_fit = scale_to_fit;
gtk_widget_queue_resize(GTK_WIDGET(self));
g_object_notify_by_pspec(
G_OBJECT(self), view_properties[PROP_SCALE_TO_FIT]);
return TRUE;
}
static gboolean
set_scale(FastivView *self, double scale)
{
self->scale = scale;
g_object_notify_by_pspec(
G_OBJECT(self), view_properties[PROP_SCALE]);
return set_scale_to_fit(self, false);
}
static gboolean
fastiv_view_scroll_event(GtkWidget *widget, GdkEventScroll *event)
{
FastivView *self = FASTIV_VIEW(widget);
if (!self->surface)
return FALSE;
if (event->state & gtk_accelerator_get_default_mod_mask())
return FALSE;
switch (event->direction) {
case GDK_SCROLL_UP:
return set_scale(self, self->scale * SCALE_STEP);
case GDK_SCROLL_DOWN:
return set_scale(self, self->scale / SCALE_STEP);
default:
return FALSE;
}
}
static gboolean
fastiv_view_key_press_event(GtkWidget *widget, GdkEventKey *event)
{
FastivView *self = FASTIV_VIEW(widget);
if (event->state & gtk_accelerator_get_default_mod_mask())
return FALSE;
switch (event->keyval) {
case GDK_KEY_1:
return set_scale(self, 1.0);
case GDK_KEY_plus:
self->scale *= SCALE_STEP;
return set_scale(self, self->scale * SCALE_STEP);
case GDK_KEY_minus:
return set_scale(self, self->scale / SCALE_STEP);
case GDK_KEY_f:
return set_scale_to_fit(self, !self->scale_to_fit);
}
return FALSE;
}
static void
fastiv_view_class_init(FastivViewClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS(klass);
object_class->finalize = fastiv_view_finalize;
object_class->get_property = fastiv_view_get_property;
view_properties[PROP_SCALE] = g_param_spec_double(
"scale", "Scale", "Zoom level",
0, G_MAXDOUBLE, 1.0, G_PARAM_READABLE);
view_properties[PROP_SCALE_TO_FIT] = g_param_spec_boolean(
"scale-to-fit", "Scale to fit", "Scale images down to fit the window",
TRUE, G_PARAM_READABLE);
g_object_class_install_properties(
object_class, N_PROPERTIES, view_properties);
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
widget_class->get_preferred_height = fastiv_view_get_preferred_height;
widget_class->get_preferred_width = fastiv_view_get_preferred_width;
widget_class->size_allocate = fastiv_view_size_allocate;
widget_class->realize = fastiv_view_realize;
widget_class->draw = fastiv_view_draw;
widget_class->scroll_event = fastiv_view_scroll_event;
widget_class->key_press_event = fastiv_view_key_press_event;
// TODO(p): Later override "screen_changed", recreate Pango layouts there,
// if we get to have any, or otherwise reflect DPI changes.
gtk_widget_class_set_css_name(widget_class, "fastiv-view");
}
static void
fastiv_view_init(FastivView *self)
{
gtk_widget_set_can_focus(GTK_WIDGET(self), TRUE);
self->scale = 1.0;
}
// --- Picture loading ---------------------------------------------------------
// TODO(p): Progressive picture loading, or at least async/cancellable.
gboolean
fastiv_view_open(FastivView *self, const gchar *path, GError **error)
{
cairo_surface_t *surface = fastiv_io_open(path, error);
if (!surface)
return FALSE;
if (self->surface)
cairo_surface_destroy(self->surface);
self->surface = surface;
set_scale_to_fit(self, true);
return TRUE;
}